This project will examine the health and mortality risks of co-resident grandparents, parents (if present), and grandchildren, and document the demographic and socioeconomic factors that are associated with the health of all family members. Despite the central role of co-resident grandparents in many families, and the importance of family structure for people's health, little research examines the relationship between families with co-resident grandparents and the health of all family members. Between 1970 and 2004 there was a 73% increase in the percentage of children under age 18 living with their grandparents, and in 2000 nearly 5.6 million grandparents lived with grandchildren aged 18 or younger. But co-resident grandparents and their families are very likely to live in poverty and to spend over 30% of their income on rent, suggesting that they might also be at increased risks of poor health. Prior research in this area is frequently limited by data with little race/ethnic or socioeconomic diversity, few health or socioeconomic variables, lack of information on all co- resident family members, and small, regional samples. We use nationally representative, cross-sectional data from the 1985-2006 waves of the National Health interview Survey (NHIS), and prospective data that links adults aged 18 and older in the 1986-2000 NHIS data to deaths in the National Death Index (NDI) through 2002. These data hold 50,894 grandparents (contributing 7,059 deaths), 51,590 parents (contributing 1,006 deaths), and 59,429 grandchildren. Analyses of grandparents and parents will examine both cross-sectional health and prospective mortality, but analyses of grandchildren will focus only on cross-sectional health measures because those under age 18 are not linked to mortality to protect their identities (too few grandchildren are aged 18 or older to examine their risks of death). Specifically, we aim to (1) examine whether the presence of co-resident grandchildren, parents, or grandparents is associate with the health of other family members;(2) examine whether there are race/ethnic differences in the relationship between family structure and health among grandparents, parents, and grandchildren;(3) examine whether the gender composition of the family is associated with health among grandparents, parents, and grandchildren;(4) examine whether the age composition of the family is associated with health among grandparents, parents, and grandchildren;and (5) examine whether the relationship between family structure and health varies by individual and family level socioeconomic status among grandparents, parents, and grandchildren. The findings from this research will advance our knowledge of the relationship between extended family structures and health, and could help policy makers and public health professionals identify the families that are at greatest risk of poor health. The primary goal of this project is to examine the health and mortality risks of co-resident grandparents, parents (if present), and grandchildren, and to document the social, demographic, and economic factors that are associated with the health of all family members. We use data from the nationally representative National Health Interview Survey that surveys all individuals in sampled households;offers detailed cross-sectional data on health, socioeconomic status, and demographic background;and has links to prospective mortality for adults aged 18 and older via the National Death Index.